def calculate_discounted_price(original_price, discount_rate=0.88,coupon=0):
    discounted_price = original_price*discount_rate
    final_price = discounted_price-coupon
    min_price = original_price*0.5
    final_price = max(min_price, final_price)
    return final_price

print(calculate_discounted_price(100,0.88,30))